Scalable Interlayer Nanostructure Design for High-Rate (10C) Submicron Silicon-Film Electrode by Incorporating Silver Nanoparticles

Abstract

High C-rate capability at 10C is a key performance indicator for the commercialization of the next-generation high-charging lithium microbattery. However, silicon (Si) anode satisfying the prerequisite high specific capacity suffers from poor electron/ionic conductivity, seriously limiting the 10C rate capability. Accordingly, we propose the strategy of inserting highly conductive silver nanoparticles (AgNPs) as an interlayer between two RF-sputtered amorphous Si thin films to form an Si/Ag/Si multilayered anode, with the density and spatial distribution of the AgNPs well-controlled by thermal evaporation. This strategy is exclusively beneficial to scale up film thickness for higher capacity. Without AgNPs, the 10C rate performance of the double-layer Si (D_Si) is worse than the single layer (S_Si) in the same total thickness, suggesting the adverse effect of the interface. However, this situation is progressively improved with the AgNPs density incorporated at the interface, where the densest AgNPs anode (D_SiAg3) demonstrated a noticeable improvement reaching 1250 mAh/g at 10 C with a 46% capacity retention rate. By scaling up to triple layers, T_SiAg3 performed the superior 10C rate capability to T_Si, testifying to the scalable potential of the unique design for boosting high-power batteries. Finally, with electrochemical impedance spectroscopy results, a possible mechanism to explain the enhancement in rate capability is subject to where Li-ion diffusion is accelerated by the charge-induced electric field condensing around the AgNPs. This design for a multilayered nanocomposite can contribute to the design and fabrication of high-charging batteries and battery-on-chip.

Binder-Free Intertwined Si and MnO2 Composite Electrode for High-Performance Li-Ion Battery Anode

“…During the first discharge, the cathodic peak appears near 0.25 V is attributed to the irreversible lithiation of the Si–O surface layer, , and the peaks disappear in the following cycles. The cathodic peak around 0.01 and 0.17 V corresponds to Li + embedding into Si to form the Li–Si alloy, while the two anodic peaks at 0.30 and 0.48 V are due to the Li + extraction forming Li x Si alloy. − In the subsequent cycles, the broad and weak cathodic peak at around 0.60 V could be ascribed to the formation of a solid electrolyte interface (SEI) of the electrolyte decomposition.…”

Waterbed inspired stress relaxation strategies of patterned silicon anodes for fast-charging and longevity of lithium microbatteries

“…A Si thin film of 300 nm in thickness was deposited on all the samples with different patterns to form a patterned-Si thin film by RF magnetron sputtering, under the same sputtering conditions as those in our previous work. 48 Before the coin cell assembly, all the Cu microgrids were removed. The process flowchart is shown in Fig.…”